Endocrinology Practice Questions

Q: A physician is evaluating a patient with hypogonadotropic hypogonadism and anosmia. What condition is most likely suspected in this scenario?

Kallmann syndrome. ***Kallmann syndrome*** - This syndrome is characterized by **hypogonadotropic hypogonadism** (due to GnRH deficiency) combined with **anosmia** (impaired sense of smell) or hyposmia [1]. - The anosmia results from the **agenesis or hypoplasia of the olfactory bulbs and tracts**, which is a key diagnostic feature. *Asherman's syndrome* - This condition is characterized by **intrauterine adhesions** or synechiae, usually occurring after uterine surgery or infection. - It primarily causes **secondary amenorrhea** and infertility but does not involve hypogonadotropic hypogonadism or anosmia. *Stein-Leventhal syndrome* - This is an older term for **Polycystic Ovary Syndrome (PCOS)**, characterized by **anovulation**, hyperandrogenism, and polycystic ovaries [1]. - It is associated with **insulin resistance** and metabolic dysfunction but not anosmia or hypogonadotropic hypogonadism. *Sheehan's syndrome* - This is a form of **hypopituitarism** caused by **ischemic necrosis of the pituitary gland** following severe postpartum hemorrhage [1]. - It leads to deficiencies in various pituitary hormones, including gonadotropins, but it is typically acute postpartum and does not present with anosmia.

Q: Which of the following is the MOST specific finding in primary hypothyroidism?

High TSH. ***High TSH*** - A **high TSH** (thyroid-stimulating hormone) is the most specific indicator of **primary hypothyroidism** because it reflects the pituitary gland's attempt to stimulate a failing thyroid gland [1]. - In primary hypothyroidism, the thyroid gland itself is unable to produce sufficient thyroid hormones, leading to a feedback mechanism that increases TSH secretion [1]. *Low T3* - While **low T3** (triiodothyronine) can be seen in hypothyroidism, it is often the last thyroid hormone to decrease significantly and can be associated with other conditions, such as **euthyroid sick syndrome** [1]. - Therefore, low T3 is less specific for diagnosing primary hypothyroidism than TSH levels [1]. *Low triglycerides* - **Hypothyroidism** is typically associated with **hyperlipidemia**, including **elevated triglycerides**, due to decreased catabolism of lipoproteins. - Thus, low triglycerides would be an unexpected finding in primary hypothyroidism. *High cholesterol* - **High cholesterol** is a common finding in **hypothyroidism** due to reduced clearance of LDL cholesterol [2]. - However, high cholesterol is a non-specific finding and can be caused by many other factors, such as diet, genetics, and other metabolic syndromes, making it less specific for hypothyroidism compared to TSH.

Q: Hypothyroidism with an increased TSH level is seen in all except which of the following?

Sheehan's syndrome. ***Sheehan's syndrome*** - Sheehan's syndrome is a cause of **secondary hypothyroidism** [4], meaning the problem lies in the **pituitary gland's inability to produce TSH**, leading to low TSH and low thyroid hormones. - In this condition, the TSH level would be **low or inappropriately normal**, not increased, as the pituitary is damaged [2]. *Lithium carbonate therapy* - Lithium can **inhibit thyroid hormone release** and synthesis, leading to **primary hypothyroidism** where the thyroid gland is the culprit. - This results in a feedback loop that causes the pituitary to produce **increased TSH** to try and stimulate the failing thyroid [1]. *Post radioiodine ablation* - Radioiodine ablation **destroys thyroid cells**, leading to a direct inability of the thyroid gland to produce sufficient hormones. - This condition mimics spontaneous primary hypothyroidism, causing the pituitary to release **increased TSH** in an attempt to stimulate the damaged thyroid [1][3]. *Endemic goitre* - Endemic goitre is often caused by **iodine deficiency**, which impairs the thyroid's ability to synthesize thyroid hormones. - This is a form of **primary hypothyroidism** leading to **increased TSH** as the pituitary tries to compensate for the low thyroid hormone levels [1].

Q: What is the fasting blood glucose level that confirms a diagnosis of diabetes mellitus?

≥126. ≥126 - A fasting plasma glucose (FPG) level of ≥126 mg/dL on two separate occasions is a diagnostic criterion for diabetes mellitus [1]. - This threshold indicates persistent hyperglycemia beyond what is considered normal. <100 - A fasting plasma glucose level 200 - A random plasma glucose (RPG) level >200 mg/dL with classic symptoms of diabetes (e.g., polyuria, polydipsia, unexplained weight loss) can confirm diabetes [1]. - However, for a fasting blood glucose alone to confirm diabetes, it needs to be ≥126 mg/dL, and a level >200 mg/dL would be an even more severe manifestation.

Q: A 35-year-old female with a history of diabetes presents with a painless neck swelling that moves with swallowing. She also reports constipation, weight gain, hoarseness, oligomenorrhea, and mild paresthesias. Examination reveals bradycardia, cold extremities, non-pitting edema, and delayed relaxation of deep tendon reflexes. Thyroid function tests show high TSH and low unbound T4 levels. Laboratory workup also reveals positive thyroid peroxidase antibodies, consistent with autoimmune thyroiditis. Given this condition, which type of cancer is she at risk of developing?

Papillary thyroid carcinoma. ***Papillary thyroid carcinoma*** - The patient's **TSH elevation**, low T4, and presence of **TPO antibodies** suggests Hashimoto's thyroiditis, which is associated with a higher risk of developing papillary thyroid carcinoma. - Symptoms such as a **firm thyroid nodule** and hoarseness raise suspicion for malignancy, especially in the context of autoimmune thyroid disease. *Follicular thyroid carcinoma* - Typically presents with **cold nodules** on radioactive iodine uptake and is less associated with autoimmune conditions than papillary carcinoma. - The clinical and laboratory features presented are more indicative of **papillary thyroid carcinoma** rather than follicular. *Anaplastic thyroid carcinoma* - Typically presents in older patients, often with a **rapidly enlarging neck mass** and significant **symptoms of obstruction**. - This case lacks key features like aggressive clinical presentation and is more consistent with **differentiated thyroid cancers**. [1] *Medullary thyroid carcinoma* - Arises from **C-cells (parafollicular cells)** and may be associated with **MEN syndromes**. - Not related to **TSH/T4 levels** or autoimmune thyroid conditions, and typically presents with **elevated calcitonin levels**.

Q: Which of the following is not a known cause of osteoporosis?

Hypoparathyroidism. ### Hypoparathyroidism - This condition leads to **low parathyroid hormone (PTH)** levels, resulting in **decreased serum calcium** and **increased serum phosphate**. - While it can affect bone metabolism, severe cases typically present with **increased bone mineral density** or **osteosclerosis**, not osteoporosis, due to reduced bone resorption. *Sarcoidosis* - This granulomatous disease can cause **hypercalcemia** due to extrarenal production of **calcitriol** (1,25-dihydroxyvitamin D) by activated macrophages. - The resulting hypercalcemia and prolonged high calcitriol levels can lead to **increased bone turnover** and **osteoporosis** [4]. *Old age* - Bone density naturally declines with age, especially after menopause in women due to **estrogen deficiency** [3]. - This age-related bone loss is a primary factor in the development of **primary osteoporosis** [2]. *Steroid therapy* - **Glucocorticoid-induced osteoporosis** is a common cause of secondary osteoporosis [1]. - Steroids decrease osteoblast activity, increase osteoclast activity, and impair calcium absorption, all contributing to **bone loss** [1].

Q: All of the following can cause osteoporosis, except which of the following?

Fluorosis. ***Fluorosis*** - **Fluorosis** is a condition caused by excessive fluoride intake, which leads to **increased bone density** (osteosclerosis) and abnormal bone formation, not osteoporosis. - While it can cause bone pain and weakness, its characteristic effect is **hardening of bones**, making them brittle but denser, rather than porous. *Steroids* - Prolonged use of **glucocorticoids (steroids)** is a common cause of secondary osteoporosis [1]. - They decrease osteoblast activity and increase osteoclast activity, leading to **reduced bone formation** and **increased bone resorption** [1]. *Thyrotoxicosis* - **Thyrotoxicosis**, or hyperthyroidism, causes an increase in bone turnover with a greater increase in **bone resorption** than formation. - This imbalance results in **net bone loss** and can lead to osteoporosis. *Hyperparathyroidism* - **Primary hyperparathyroidism** leads to excessive secretion of parathyroid hormone (PTH), which continuously stimulates osteoclasts. - This results in **increased bone resorption**, particularly from cortical bone, causing osteoporosis.

Q: Ulcers in diabetes are precipitated by all of the following factors except:

Insulin therapy. ***Insulin therapy*** - **Insulin therapy** is a treatment for diabetes that helps regulate blood sugar levels, and it does not directly precipitate ulcers [1]. - While poorly controlled diabetes (which insulin therapy aims to prevent) can lead to complications, insulin itself is not a cause of ulcers. *Vascular insufficiency* - **Vascular insufficiency**, particularly **peripheral artery disease**, reduces blood flow to the extremities, impairing tissue healing and increasing the risk of ulcers [1], [4]. - Reduced blood supply makes tissues more vulnerable to minor trauma and infection, leading to ulcer formation and poor wound healing [2]. *Neuropathy* - **Diabetic neuropathy**, especially **peripheral sensory neuropathy**, leads to a loss of protective sensation, meaning patients cannot feel pressure, pain, or injury to their feet [1]. - This lack of sensation allows repeated trauma and pressure to go unnoticed, creating sites for ulcer formation, often combined with motor neuropathy causing foot deformities [1]. *Microangiopathic changes in blood vessels* - **Microangiopathic changes** affect small blood vessels, leading to reduced tissue perfusion and oxygenation [3]. - These changes contribute to poor tissue health, making the skin more fragile and less able to withstand minor injuries, thereby increasing ulcer risk [3].

Q: Which of the following conditions is the most common complication of radioiodine treatment for Graves' disease?

Hypothyroidism. ***Hypothyroidism*** - **Radioiodine (RAI) therapy** destroys overactive thyroid cells, making it highly effective for Graves' disease but often leading to a permanent state of **hypothyroidism** post-treatment. - The goal of RAI is to eliminate the source of excess hormone production, and while effective, it frequently necessitates lifelong **thyroid hormone replacement**. *Thyroid storm* - **Thyroid storm** is a rare, life-threatening complication, usually seen in untreated or undertreated hyperthyroidism or during acute stress, not typically a direct outcome of effective RAI. - While a transient increase in thyroid hormones can occur shortly after RAI, a full-blown thyroid storm is infrequent with proper preparation and management. *Thyroid cancer* - There is no significant evidence to suggest an increased risk of **thyroid cancer** in adults following therapeutic doses of radioiodine for Graves' disease [1]. - The radiation dose is targeted primarily at the thyroid gland, and studies have shown no clear link to increased malignancy [1]. *Subacute thyroiditis* - **Subacute thyroiditis** (also known as de Quervain's thyroiditis) is typically a post-viral inflammatory condition of the thyroid, characterized by pain and tenderness in the thyroid gland [2]. - It does not directly result from radioiodine treatment; however, some patients may experience a transient inflammatory response (radiation thyroiditis) after RAI, which is usually mild and self-limiting, not true subacute thyroiditis.

Question 1

What is the most appropriate insulin regimen for achieving tight control of blood sugar levels in a 20-year-old male with type 1 diabetes mellitus?

Accepted Answer

Morning injections of insulin detemir with insulin aspart at mealtimes.

Answer

Morning injection of NPH insulin and evening injection of regular insulin.

Answer

Morning injections of insulin lispro with evening injections of insulin glulisine.

Answer

Evening injections of mixed regular insulin and insulin glargine for basal control.

Question 2

A physician is evaluating a patient with hypogonadotropic hypogonadism and anosmia. What condition is most likely suspected in this scenario?

Accepted Answer

Kallmann syndrome

Answer

Asherman's syndrome

Answer

Stein-Leventhal syndrome

Answer

Sheehan's syndrome

Question 3

Which of the following is the MOST specific finding in primary hypothyroidism?

Accepted Answer

High TSH

Answer

Low T3

Answer

Low triglycerides

Answer

High cholesterol

Question 4

Hypothyroidism with an increased TSH level is seen in all except which of the following?

Accepted Answer

Sheehan's syndrome

Answer

Post radioiodine ablation

Answer

Endemic goitre

Answer

Lithium carbonate therapy

Question 5

What is the fasting blood glucose level that confirms a diagnosis of diabetes mellitus?

Accepted Answer

≥126

Answer

>200

Answer

<100

Answer

101-125

Question 6

A 35-year-old female with a history of diabetes presents with a painless neck swelling that moves with swallowing. She also reports constipation, weight gain, hoarseness, oligomenorrhea, and mild paresthesias. Examination reveals bradycardia, cold extremities, non-pitting edema, and delayed relaxation of deep tendon reflexes. Thyroid function tests show high TSH and low unbound T4 levels. Laboratory workup also reveals positive thyroid peroxidase antibodies, consistent with autoimmune thyroiditis. Given this condition, which type of cancer is she at risk of developing?

Accepted Answer

Papillary thyroid carcinoma

Answer

Follicular thyroid carcinoma

Answer

Anaplastic thyroid carcinoma

Answer

Medullary thyroid carcinoma

Question 7

Which of the following is not a known cause of osteoporosis?

Accepted Answer

Hypoparathyroidism

Answer

Sarcoidosis

Answer

Old age

Answer

Steroid therapy

Question 8

All of the following can cause osteoporosis, except which of the following?

Accepted Answer

Fluorosis

Answer

Steroids

Answer

Thyrotoxicosis

Answer

Hyperparathyroidism

Question 9

Ulcers in diabetes are precipitated by all of the following factors except:

Accepted Answer

Insulin therapy

Answer

Microangiopathic changes in blood vessels

Answer

Vascular insufficiency

Answer

Neuropathy

Question 10

Which of the following conditions is the most common complication of radioiodine treatment for Graves' disease?

Accepted Answer

Hypothyroidism

Answer

Thyroid cancer

Answer

Thyroid storm

Answer

Subacute thyroiditis

Endocrinology — MCQs

Endocrinology — MCQs

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